Machine for crushing, selecting and sifting materials



June 17, 1958 P. R. HIPPERT 2,339,251

MACHINE FOR CRUSHING, SELECTING AND SIFTING MATERIALS Filed March 16, 1953 MATERIAL.

1 INVENTOR I 1 HEQA E F5004 HPPERT BY @LAMMSW ATTORNEY 2,839,255! Patented June 17, 1958 MACHINE FOR CRUSHING, SELECTING AND SIFTING MATERIALS Pierre Raoul Hippert, Billancourt, France, assignor of one-half to Societe Anonyme Les Ateliers Reunis Broyeurs Forplex, a corporation of France Application March 16, 1953, Serial No. 342,583

Claims priority, application France March 19, 1952 9 Claims. (Cl. 241-56) The present invention relates to improvements in crushing or pulverizing machines and in particular to an improved pulverizing, selecting and sifting machine which permits of the obtaining of a regulatable degree of fineness of the crushed material of the order of one micron.

Crushing machine are known in which the material to be crushed is subjected to successive blows between rotatable members driven at high speed, and stationary members, and in which use is made of the mutual friction between the particles of material against one another to effect crushing. In some instances these machines comprise discs between which are interposed vanes which may carry percussion hammers, said discs rotating inside a crushing chamber, provided at its periphery with stationary percussion members with respect to which the said discs extend in close proximity, with the admission of the material to be crushed, and air, taking place axially with respect to the machine, and the material and the air being projected by centrifugal force over the entire width of the crushing chamber.

Crushing machines are also known in which the crushing action is completed by exerting upon the material already crushed, a cyclonic action, which tends to draw the crushed particles out of the crushing zone. In some of the crushing machines, use is made of an independent selector, with the selection being performed in a chamber into which air, and the material to be crushed, are intro duced at the periphery of the chamber and drawn towards the axis of the selector. Other known crushing machines comprise a selector which is combined with the crushing machine and in which the material to be crushed is introduced axially into the machine and subjected to a crushing action and is carried along towards the periphery of the machine by centrifugal force. The particles which are fine enough, are then sucked towards the axis of the machine with a cyclonic motion, the inlet aperture and the outlet aperture for the material being disposed to face each other.

In connection with these known crushing machines the objection exists that under some conditions of operation circular, or annular, layers of particles may gather during the cyclonic selection and remain in a state of equilibrium between the centrifugal force and the cyclonic suction. These particles, which are of determined size. are no longer subjected to the crushing action, and prevent the machine from operating satisfactorily.

It is an important object of the present invention to provide an improved machine of the above described kind which is free from the above objection and is capable of yielding crushed particles, the fineness of which can be adjusted at the operators discretion, and may be of the order of one micron, and in which oversize particles are automatically rejected.

It is a further object of the invention to provide a machine of the above kind in which the working chamber, into which the material to be treated is introduced, is sub-divided in such manner as sequentially to crush the material, to both crush and select the material, and to crush and sift the material. with oversize particles being rejected in the sifting zone, or returned to the working chamber, and the initially 'rushed material being subjected and exposed to a cyclonic suction action in the crushing and selecting zone.

Thus, according to the invention, a crushing, selecting and sifting machine for solid material is provided, comprising a working chamber, preferably of cylindrical form and having an interior roughened or interrupted working surface, said chamber having a rotatable device mounted therein which delivers the material against said surface and receives the material from a tangentially disposed inlet duct, and the construction and arrangement being such that the material is constrained to travel axially along said chamber while being subjected to the cylonic suction effect of an axial air suction duct opening into said rotatable device. The rotatable device is conveniently formed by a pair of axially spaced vertically disposed discs mounted to rotate about a horizontal axis and connected by axial vanes which are arranged in circumferentially spaced annular assembly and extend into close proximity to said working surface, with one said disc being disposed adjacent one end wall of the working chamber and the other disc having the axial suction duct connected thereto and opening into the space between the discs.

The tangential inlet port for the material to be crushed is located between the first said end wall and its adjacent disc of the rotatable device and a tangential air inlet port extends along the entire length of the working chamber, which chamber is divided by the two discs into three axially spaced zones which communicate with one another through the space provided between the said Working surface and the outer peripheries of the vanes, which zones provided a crushing zone, formed between the first said end wall and the adjacent disc of the rotatable device, into which zone the material is introduced, followed by a crushing and selecting zone, formed between the two discs. and by a crushing and sifting zone, formed between the other disc and the adjacent end wall of the working chamber. The axial cyclonic suction channel only communicates with the selecting zone provided between the two discs. This selecting zone is itself sub-divided into a series of radial pockets extending between the discs and formed by the axial vane assembly, said pockets opening at their outer peripheries to the said working surface and, at their inner peripheries, to the said axial suction duct.

The material to be crushed which enters the first said zone is carried along and rotated with the rotatable device and subjected to a crushing action on the major portion of the said operating surface of the operating chamber. During the course of this rotation, and owing to the relative arrangement of the discs, and of hammers associated with the rotatable device, the crushed particles are constrained to travel along a substantially helical path, the pitch of which is related to the size of these particles. At the same time. centrifugal force maintains these particles against the working surface. As the particles come in front of the air inlet, the particles are subjected to a selecting action where the particles, which have attained the desired degree of fineness, are subjected to the cyclonic suction and delivered by the axial suction duct into a receiving member associated with the crushing machine, while the larger or oversize (or too hard) particle follow their rotational path along the working chamber.

The degree of fineness of the crushed particles may be varied by altering the speed of rotation of the rotatable device, adjusting the intensity of the cyclonic suction, or by adjusting the space between the vanes and the working surface.

The arrangement will be such that oversize, or harder,

particles will be rejected from the suction duct and directed to the final crushing and sifting zone.

An important feature of the present invention resides in the final sifting chamber provided adjacent the discharge end of the working chamber and conveniently communicating with this chamber through an annular space. Oversize, or harder particles, penetrate into this sifting chamber in counter-flow relation to an adjustable air flow created within the sifting chamber, whereby a proportion, or all. of such particles may be returned to the working chamber for further treatment or be collected from the sifting chamber.

Further objects and advantages of the invention, residing in the construction, arrangement and combination of parts will appear clearer from a consideration of the following description of one form of the invention. by way of example, with reference to the accompanying drawings, and from the appended claims.

In the drawings:

Fig. l is a longitudinal sectional view of the machine on the line ll of Fig. 2, and

Fig. 2 is a transverse sectional view through the working chamber.

The machine, as illustrated, comprises .1 generally cylindrical working chamber 1 the inner wall of which carries small bars 2 providing a rough surface and surrounded by a casing 3 through which a cooling fluid may flow. The chamber 1 is closed at one end by an end plate 4 connected to a yoke member through which :1 shaft 5 is journalled by means of ball or roller bearings 6-6. The periphery of the yoke member maintains the small bars 2 within slots in the working surface of the chamber 1. A deflector 7 is provided inside the chamber 1, adjacent the cover plate 4. for preventing particles of the material being treated from penetrating into the bearings 6-6.

Within the chamber 1 there is rotatably supported a rotary turbine-like device 8 rigidly secured upon the shaft 5, as by means of a keyed sleeve 9. Said rotary device comprises two discs 1i and 11 interconnected by vanes 12 extending axially between these discs and projecting therefrom on both sides into close proximity with the end walls of the working chamber and, at their outer peripheries, into clos proximity to the interior Cylindrical working surface of the chamber 1. The disc 10 provides a closed surface. while the disc 11 has a central orifice through which the axial air suction duct 23 extends. This duct is adapted for connection with the suction fan, not shown. The vanes l2 may be fitted on their periphery with interchangeable wear-taking plates or hammer elements. The vanes are arranged in circumferentially spaced annular assembly and define radially extending pockets between them, as are seen in Fig. 2.

The discs 10, 11 subdivide the chamber 1 into three axially spaced zones communicating with one another at their outer peripheries and con. .tuting a crushing zone 13, an intermediate crushing and selecting zone 14. and a crushing and shifting zone 15.

The cylindrical working chamber 1 is partly closedotl at its delivery end by an annular partition 16 secured to the end portion 17 of the suction duct .23 and providing an annular slot l3 between its outer periphery and the chamber 1. This slot 58 provides communication between the chamber 1 and a final sitting chamber t9, provided around its outer periphery with a. cylindrical or conical partition 2i, which acts as a deflector and defines an annular space 2t"! into which the outer air may penetrate through an adjustable port 27. The portion of the sifting chamber i defined by the dcllcctor 21 has an adjustable suction port 28 and communicates with an air-tight receiver device (not shown) whicn collects the particles separated by the resulting sitting action.

The vanes 12 of the rotary device it may be either plane and radially disposed. or be obliquely arranged with respect to the suction end 17 of the pipe 23.

lil

Provided for the inflow of the material to be crushed and for the intake of air there is a duct 24 forming an air shaft in which a chute terminates, which chute communicates with the distributor (not shown) by which the material to be crushed is fed into the portion of the cylindrical working chamber 1 situated opposite to the suction duct 23. Said chute includes a vertical or slightly inclined partition 29 which divides the duct 24 into two parts. The part situated at the end opposite to the suc-- tion pipe permits the inflow of the material to be crushed with a portion of the sucked air, whereas the other part is located in front of the suction zone, exclusively, and serves for the introduction of the selecting air. The small bars 2 continue in front of the entire width of duct 24, where these bars are designated in Fig. 2 by the reference 25. Their purpose, at this position, is to breakup and sub-divide the layer of material subjected to the crushing operation as this material leaves the actual crushing zone and is about to enter the selecting zone, arranged in front of the duct 24. The reference 26 designates interchangeable blades provided on the vanes or hammers 12.

The operation of the machine as above described is as follows:

The material to be crushed, which is poured regularly and with such an outflow that the power taken by the rotatable device 8 remains constant by means of an adjustable distributor, penetrates through the duct 24 into the zone 13 of the working chamber, with a part of the sucked air, in a direction substantially tangential to the circumference defined by the peripheries of the hammers 26 of the device 8. It is then carried along in rotation and crushed by the successive blows to which it is subjected between the hammers 26 and the small bars 2, and is spread under the action of the centrifugal force against the peripheral interior wall (the working surface) of the chamber 1. Under the joint action of the centrifugal force and of the axial suction from the duct 23, the material follows substantially hclicals paths from the entry end towards the delivery end of. the working cham ber 1 with the pitch of the helicoids being a function of the size and of the hardness of the particles.

The layer, constituted by particles of different size, applied against the periphery of the working chamber is subdivided by the action of the hammers 26 and the vanes 12 into a number of strips, each of which is carried along by one of the pockets defined inside the working chamber by the vanes 12. In the course of their rotation, these strips of material present themselves successively before the tangential duct 24. The air sucked from this duct 24 towards the suction orifice of the axial duct 23 flows through this strip of material inside each pocket defined by the vanes 12 and carries along, towards the axis, the particles which have reached such a size that the centrifugal force exerted on them by the rotational speed is smaller than the centripetal force resulting from the suction and the friction forces produced by the air flow in this pocket.

As a result of the joint action of these forces, a helical dragging of the particles, which are brought by suction up to the duct 23, takes place.

When the pocket being considered has been moved through such an angle that it is no longer opposite the duct 24, the centrifugal force becomes preponderant and the particles, the helical paths of which were too long to allow of their penetration into the duct 23, are forced back towards the periphery of the working chamber 1 and subjected to a further crushing cycle. This phenomenon takes place separately for each of the pockets defined inside the Working chamber by the vanes 12.

It will be seen that the principle of the operation of the crushing, selecting and sifting machine according to the invention is quite different from the known machines as to the crushing device including a rotatable plate comprising two discs between which vanes are arranged which project the air and the material towards the periphery of the working chamber compared with the known cyclonical selection device which comprises rotatable discs between which is exerted the action of the air sucked towards the centre, but which have no vanes defining pockets in which the axial suction action takes place selectively.

The larger or harder particles will reach the end of the working chamber 1 without having attained the required degree of fineness to permit of their being drawn toward the axial suction duct 23. Such particles then tend, due to their helical movement, to escape from this chamber through the slot 18. In front of this slot, the particles undergo a sifting action, due to the suction of the air drawn from the duct 23 and flowing through the sifting chamber 19 and the port, or ports, 27. The finer particles may, depending upon the degree of throttling of the sitting air which can be ascertained by means of an appropriate device) be returned into the chamber 1 for undergoing a further crushing action. A further small sifting action is performed rearwardly of the slot 18 due to the action of an adjustable air stream, which may be introduced into the space 20, defined by the deflector 21, through ports 27, or through ports 28, preferably provided at the lower part of the sifting chamber 19. The air streams can only penetrate through the ports 27, 28, which may be opened either separately or simultaneously, either wholly or partly. The air stream, or streams, intersect at right angles, or obliquely, the layer of particles which leave the chamber 1 through the slot 18. Still a further portion of these particles may therefore be returned into the chamber 1 for being subjected to a further crushing action. The evacuation of the refuse takes place either through a revoluble fluid-tight valve (not shown) or directly into a removable fluid-tight container (also not shown).

A suitable adjustment permits, if desired, the entire quantity of the products to be sent back to the chamber 1, whereby the same machine may be operated either as an integral crusher, for example, in the case of a pure material, or as a crusher involving an automatic sifting action, when dealing with a material containing hard particles which it is more difiicult to pulverize.

Having thus disclosed my invention, what I claim as novel and wish to secure by Letters Patent is as follows:

1. In a machine for crushing, selecting and sifting materials and permitting a regulatable degree of fineness of the order of one micron to be obtained, casing structure defining a hollow working chamber, rotary means mounted on said casing structure for rotation in said chamber, said means cooperating with the periphery of said chamher for crushing the material under treatment, peripheral and tangential duct structure on said casing and in communication with said chamber for delivering the material and air thereto and to said means, and an axial suction duct in said casing and in communication with said chamber for receiving the crushed material, said ducts being arranged axially of said chamber for crushing the material, for selecting the crushed particles by cyclonic action, and for sifting said material.

2. In apparatus for crushing and selecting solid materials, casing structure defining a crushing and selecting chamber with an inner cylindrical crushing surface, said chamber having oppositely located end walls and a side wall interconnecting said end walls and defining the periphery of said chamber, a driving shaft rotatably mounted in one of said end walls, an axial air suction duct mounted in the opposite end wall and communicating with said chambet, a revoluble body mounted in said chamber and connected with said driving shaft for rotation thereby, radial vanes mounted on said body and extending from said body into close proximity to the internal cylindrical crushing surface of said chamber, said vanes defining segmental pockets communicating with the axial air suction, crushing means mounted on the outer edge of said radial vanes for co-operating with the crushing surface of said cham bet, and an inlet for air and material provided in said side wall over a minor fraction of the periphery of said chamber, said pockets successively coming into register with said inlet during the rotational movement of said revoluble body.

3. ln apparatus for crushing and selecting solid materials, casing structure defining a crushing and selecting chamber having an internal cylindrical crushing surface, said chamber having oppositely located end walls and a side Wall interconnecting said end walls and defining the chamber periphery, a driving shaft rotatably mounted in one of said end walls, a revoluble body fast upon said driving shaft for rotation therewith, a pair of discs carried by said revoluble body, said discs extending parallel to the end walls of said chamber and dividing the latter into three :mnes consisting of a middle zone and two outer zones, an axial suction duct extending through the chamber end wall opposite to the one supporting the driving shaft and terminating in the middle zone between the two discs, radial vanes carried by said revo-luble body and dividing the chamber zones into sector-shaped compartments, said vanes extending to the immediate neighborhood of the cylindrical crushing surface of said chamber, crushing means carried by the outer edge of the radial vanes for cooperating with said crushing surface, and an inlet for the air and the material to be crushed, said inlet being formed on said side wall and extending over a minor fraction of the chamber periphery.

4. Apparatus as claimed in claim 3 in which the inlet for the air and the material to be crushed extends over the entire length of the chamber and communicates with the atmosphere, and comprising a partition extending substantially parallel to the end walls of the chamber and dividing said inlet into two parts.

5. In apparatus for crushing and selecting solid materials, casing structure defining a crushing and selecting chamber having an internal cylindrical crushing surface, said chamber having end walls and a side wall interconnecting said end walls and defining the periphery of the chamber, a driving shaft rotatably mounted in one of said end walls, a revoluble body fast upon the driving shaft for rotation therewith. a primary solid disc carried by the revoluble body and extending parallel to the end walls of the chamber, a secondary disc carried by the revoluble body and extending parallel to the primary disc. :1 central aperture in said secondary disc. said discs dividing the chamber into three zones and having a diameter smaller than the inner diameter of the chamber, said zones including a middle zone, an axial suction duct extending through the chamber end walls opposite to the end wall carrying the driving shaft, said duct terminating in the central aperture of the secondary disc for communicating with the middle zone of said chamber, radial vanes cmricd by the revoluble body and dividing the chamber zones into sector-shaped compartments, said vanes extending into close proximity with the cylindrical crushing surface of the chamber, crushing means carried by the outer edge of the radial vanes for co-operating with the crushing surface, an inlet for the air and the material to be crushed, said inlet being formed in said side wall and representing a minor fraction of the chamber periphery, and communicating with the amosphere, a partition arranged substantially opposite the primary disc and dividing said inlet into two parts, and means for introducing the mate rial to be crushed into one of said parts between the pri mary disc and the neighboring end wall of the chamber.

6. Apparatus as claimed in claim 5 wherein longitudinally extending bars are partly imbedded in the peripheral wall of the chamber, said bars also extending through the inlet for the air and the material to be crushed so as radially to direct the air admitted into the chamber through said inlet.

7. In apparatus for crushing, selecting and purifying solid materials, casing structure delineating a crushing and selecting chamber having an inner cylindrical crushing surface and an extension of the crushing chamber, said chamber having end walls and a side wall defining its periphery, a driving shaft rotatably supported by one of said end walls, an axial suction duct terminating in said chamber through the end Wall located opposite to the one carrying said shaft, a revoluble body fast upon said shaft and rotated thereby, crushing means supported by said revoluble body and co-operating with the crushing surface of the chamber, an inlet for the air and the material to be crushed, said inlet being formed in said side wall, a purifying chamber coaxially arranged in said extension of the crushing chamber, an inlet for the purifying air formed in the purifying chamber, and an annular slot providing communication between the adjacent end of the crushing chamber and the purifying chamber.

8. In apparatus for crushing, selecting and purifying solid materials, casing structure defining a crushing and selecting chamber having a inner hollow cylindrical crushing surface, said chamber having end walls and a side wall defining its periphery, a driving shaft rotatably supported by one of said end walls, a revoluble body fast upon said driving shaft for rotation therewith, a primary solid disc carried by said revoluble body and extending parallel to the end walls of the chamber, a secondary disc carried by said revoluble body and axially spaced from the primary disc, a central aperture in the secondary disc, said discs dividing the chamber into three zones and having a diameter smaller than the inner diameter of the chamber, said zones including a middle zone, an axial suction duct extending through that end wall of the chamber which is located opposite to the end wall carrying the driv- 3 ing shaft, said duct terminating in the central aperture in the secondary disc for communicating with the middle zone of said chamber, radial vanes carried by the revoluble body and dividing the chamber zones into sectorshaped compartments, said vanes extending into close proximity with the cylinder crushing surface of the chamber, crushing means carried by the outer edge of the radial vanes for co-operating with said crushing surface, an inlet for air and the material to be crushed, said inlet being formed in said side walls and representing a minor fraction of the chamber periphery, and communicating with the atmosphere, a partition arranged substantially opposite to the primary disc and dividing said inlet into two parts, means for feeding the material to be crushed into that portion delineated by said primary disc and by the neighboring end wall of the crushing chamber, said crushing chamber having an extension, means for feeding air into the space between the primary and secondary discs, a purifying chamber coaxially arranged in said extension of the crushing chamber, an inlet for the purifying air formed in the wall of the purifying chamber, and an annular slot providing communication between the adjacent end of the crushing chamber and the purifying chamber.

9. Apparatus as claimed in claim 8 wherein longitudinally extending bars are arranged in the periphery of the crushing chamber opposite to the inlet for the air and the material to be crushed so as to direct the intake air fed to the crushing chamber radially toward the sectorshaped compartment which registers with said inlet.

References Cited in the file of this patent UNITED STATES PATENTS 1,485,072 Farner Feb. 26, 1924 2,361,758 Flique Oct. 31, 1944 2,591,141 Dulait Apr. 1, 1952 

